Reddit mentions of TECKNET F27 In Car Universal Wireless FM Transmitter with 3.5mm Audio Plug and USB Car Charger

I'm your guy, I've tried tons of these. I have two setups that I can recommend.

I recommend this one the most, it's been the best and most reliable for quite some time for me. Sound quality is great. Also, it has bluetooth, which works great. Just a tip, use the bluetooth and download an app called Android Auto. It's a driving friendly interface that combines your music/podcast apps, navigation, phone app, and Google Voice commands for texts if you need. You can text by voice and it gives you the option to speak your text messages when you get them. You can also set the app to automatically start and shut off when your phone's bluetooth turns on or off.

https://www.amazon.com/gp/product/B003PPGOC0/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

Or, this one, really good so far, seems as good as the first but the first is really durable.

https://www.amazon.com/gp/product/B001AIM5ZE/ref=oh_aui_search_detailpage?ie=UTF8&psc=1


Here's a tip for the best sound quality out of these if you'll only use your FM transmitter in your car and not the radio. Unscrew the antenna out of your car and toss it in a closet or somewhere. Then a lot of low to medium signal radio stations won't interfere. Which is the cause of like 90% of the bad quality you'll hear.

If your car has a cassette player you can use a cassette adapter http://www.amazon.com/RCA-AH600R-Car-Cassette-Adapter/dp/B000BUN79K/

or you can try an fm transmitter. It broadcasts a radio signal at a certain frequency and you simply set your car radio to that frequency. http://www.amazon.com/Patuoxun-Transmitter-Adapter-Galaxsy-Charger/dp/B00GLPG03Y/

http://www.amazon.com/TeckNet-F27-Car-Universal-Transmitter/dp/B001AIM5ZE/

You can listen to the music on your phone through your radio with this device.

We're not talking about the same thing. Mine was something like this: https://www.amazon.com/TeckNet-F27-Car-Universal-Transmitter/dp/B001AIM5ZE/ This avoids having to have bluetooth & an aux input on the head unit.

I hate to break it to you, but that wont work unless you can actively power the speaker. a bare 3.5 cable does not carry near enough the wattage you would need.
If you still have the head unit, you may be able to terminate a 3.5 cable off of that, but i do not know enough about radio to tell you that. what would definatly work if you still have the head unit. is a car FM/3.5 conversion kit, buy a small FM antenna, and one of these https://www.amazon.com/gp/product/B001AIM5ZE Boom, localized radio station, pro is that it would even be wireless
(To an extent)

I just bought and set up one of these for a totally non technical relative, they love it..

https://www.amazon.com/gp/product/B001AIM5ZE/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

It's operating fine in a major metro area.

I use this cheap FM transmitter with an audio jack.

I got this one cheap as fuck and it works well

Plug in a radio transmitter and use your phone. Why use something inefficient like CDs when you have a better and affordable option. CDs aren't even that old, if you want to be an "old soul" you could at least use cassettes.

https://www.amazon.com/TeckNet-F27-Car-Universal-Transmitter/dp/B001AIM5ZE/ref=sr_1_7?ie=UTF8&qid=1497670909&sr=8-7&keywords=Car+fm+transmitter

Tbh I got a £9.99 one off amazon that covers the entire fm spectrum and use it throughout Central london regularly on 89.5. Never have to change frequency and it sounds as good as listening to a powerful radio station. I'm pretty happy with it! Years ago I had one I paid like £35 and it was abysmal at best even in rural areas. Just found which one it is in case somebody is interested: TeckNet® In Car Universal FM Transmitter - http://amazon.co.uk/dp/B001AIM5ZE